Flickering lights, a socket that’s gone dead, or a breaker that keeps tripping for no obvious reason — these are some of the calls we get asked about most, second only to RCD trips. Fault finding is often treated as a mystery, but it follows a fairly logical process. Here’s what’s actually going on, and when it’s worth calling someone in rather than resetting the breaker again and hoping.
What counts as a fault
An electrical fault is anything that stops current flowing where it should — a loose connection, damaged insulation, a failed component, or water getting somewhere it shouldn’t. Symptoms vary: some faults trip an RCD immediately, others just cause flickering or a socket that works intermittently. A fault that doesn’t trip anything is often the one that’s been ignored longest, because nothing forces you to deal with it.
Common causes we find
Loose connections at sockets or in the consumer unit are the most frequent cause of flickering and intermittent faults — a wire that was never tightened properly, or one that’s worked loose over years of expansion and contraction. Damaged cable insulation, often from drilling into a wall or from rodents in a loft, is another common one. Old wiring nearing the end of its working life shows up regularly on EICRs we carry out across Bristol. Outdoor circuits — garden lighting, sheds, hot tubs — fail more often than indoor ones simply because they’re exposed to the weather.
How we actually find a fault
It starts with narrowing down the circuit. If a whole ring or radial has gone dead, we isolate it and test with a multimeter and insulation resistance tester to check for a short or an earth fault, then work along the circuit — socket by socket, junction by junction — until the reading changes. That tells us roughly where the fault sits, so we’re not lifting floorboards along the entire run. Intermittent faults can take longer, because the fault may only show up under certain conditions, like when a circuit heats up or when it rains.
A consumer unit that’s outdated makes fault finding harder, because older units don’t isolate circuits as cleanly. If yours is due for an upgrade anyway, our guide to consumer unit replacement costs covers what’s involved.
When to call someone rather than reset it
Resetting a tripped breaker once is fine. If it trips again straight away, or keeps tripping over several days, that’s a fault, not a one-off. Burning smells, warm sockets or scorch marks mean switch off and call someone the same day — don’t keep testing it. Flickering limited to one light fitting is sometimes just a loose bulb or a failing dimmer, but flickering across multiple rooms points to something upstream and is worth getting looked at.
Who should do the work
Fault finding on fixed wiring isn’t DIY territory — our guide to what electrical work you can legally do yourself explains where the line sits. Any electrician doing this work should be registered with a competent person scheme; you can check credentials through NICEIC or NAPIT before booking anyone in. We work to BS 7671 on every job, and if a fault turns out to be part of a wider problem with the installation, we’ll tell you honestly rather than just patching the symptom.
If something in your home is tripping, flickering, or just not working properly, get in touch — we cover fault finding across Bristol and South Gloucestershire and can usually get someone out quickly.
